High-performance liquid chromatography sample capacity

Fig. 3 Chromatograms obtained by pH zone-refining CCC. (A) Separation of CBZ(Z) dipeptides. Experimental conditions are as follows apparatus type-J multilayer CPC (PC Inc., Potomac, MD, USA) with a 10-cm revolution radius column multilayer coil, 1.6-mm ID, 325 mL capacity solvent system methyl tert-h xiy ether/acetonitrile/water (2 2 3), 16 mM TEA in organic phase (pH 1.83), and 5.5 mM NH3 in aqueous phase (pH 10.62) sample eight CBZ(carbobenzyloxy) dipeptides as indicated in the chromatogram, each 100 mg in 50 mL of solvent (25 mL in each phase) flow rate 3.3 mL/hr in head-to-tail elution mode detection 206 nm revolution 800 rpm retention of stationary phase 65.1%. (B) Separation of bacitracin complex. High-performance liquid chromatography (HPLC) analysis indicated that two major components, bacitracins A and B, were isolated in peaks 3 and 5, respectively. Experimental conditions are as follows apparatus and column same as above solvent system methyl r -butyl ether/ acetonitrile/water (4 1 5), 40 mM triethylamine, 10% DEHPA in the organic stationary phase, and 20 mM HCl in aqueous mobile phase flow rate 3 mL/min sample 5 g of bacitracin dissolved in 40 mL of solvent (20 mL in each phase) revolution 800 rpm detection 280 nm.

The suspension of an SPM sample in 100mL of CH2CI2 is sonicated for 15 min and filtered with a membrane that has a 0.1-pm pore size, the filtrate is evaporated, and the residue is resolved in acetonitrile [24]. The concentration of the chemicals in the SPM extracts is determined using a multicolumn high-performance liquid chromatography (HPLC)/spectrofluorometer/computer system. According to EQ = S([PAH]iEFi +. ..+ [PAH] EF ), the chemically derived induction equivalent (EQ) is calculated to standardize the biological effect of the chemical on the EROD capacity of the Flep G2 cells [25]. 

Coupled systems include multidimensional and multimodal systems. Multidimensional chromatography involves two columns in series preferably two capillary columns, with different selectivity or sample capacity, to optimize the selectivity of some compounds of interest in complex profiles or to provide an enrichment of relevant fractions. In multimodal systems, two chromatographic methods or eventually a sample preparation unit and a chromatographic method are coupled in series. Coupled systems that received much interest in recent years are multidimensional CGC (MDCGC), the combination of high-performance liquid chromatography with CGC (HPLC-CGC) and the on- or off-line combination of supercritical fluid extraction with CGC (SFE-CGC). Multidimensional and multimodal techniques in chromatography arc described in detail in [65],... 

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